<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        var arr=["hello"];
       /* arr[1]="大家好";    
        console.log(arr);  */
         var myLength=arr.push("大家好","world",100,true);
       // arr.push("大家好");
        console.log(arr);
        console.log(myLength);

        var arr1=[100,200,300,400,500];
        arr1.pop(); //删除数组里最后一个元素
        console.log(arr1);
        
        
    </script>
</body>
</html>